• Journal of IKEEE
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• v.24 no.1
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• pp.178-185
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• 2020

This paper proposes precise time synchronization-based synchronized sampling structure applied HW/SW platform for LAN-based protection of future digital substations. The integrated software of the proposed platform includes IEC 61850 protocol, IEEE 1588 precision time protocol and synchronized sampling structure. The proposed platform expected to provide a basis of an application of future distributed sensing data-based protection and control methods by providing synchronized measurement among IEDs. The implementation of the proposed HW/SW platform technique was performed using TMDXIDK572 multi-core/multi-processor evaluation module and its time synchronization performance and synchronized sampling function were confirmed through the performance tests.

• Proceedings of the KIEE Conference
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• 2006.07a
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• pp.452-453
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• 2006

저압 개폐기는 에어컨, 냉동기, 쇼케이스, 산업용 청소기, 전기 온수기, 건조기, 공조기, 펌프, 콤프레셔 등의 모터제어 및 히터와 조명기기의 개폐 등에 광범위하게 이용되는 개폐장치이다. 저압 전자개폐기는 수 천회에서 수백만회까지 빈번한 개폐사용조건으로 인해 시험규격에서는 개폐시험을 통해 수명을 검증하도록 되어 있다. 이 개폐시험 회로는 규정된 전압, 전류, 역률 조건을 맞추기 위해 저항과 리액터를 직렬 연결하여 구성한다. 또한 모터와 같은 리액터 부하를 개폐하는 개폐기의 경우는 전류차단 순간 과도회복전압의 피크비와 주파수를 규정하여 적용하고 있다. IEC60947-1에서는 과도회복전압의 피크비와 주파수에 대한 규정값을 제시하고 있으며 제시된 값을 제어하기 위한 회로를 제시하고 있다. 과도회복전압의 피크비와 주파수는 개폐기 접점의 절연성능과 밀접한 관계가 있으며 수명에 치명적인 영향을 미친다. 본 연구에서는 LS산전(주) 부하개폐시험 회로의 과도회복전압 조건과 영향을 설명하고 제어하기 위한 저항과 커패시터를 적용하는 방법을 제안하고자 한다.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.25 no.11
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• pp.1164-1171
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• 2014

Bulk Current Injection(BCI) test is a method of injecting current into Integrated Circuit(IC) using a current injection probe to qualify the standards of Electromagnetic Compatibility(EMC). This paper, we propose a microstrip coupler structure that can replace the BCI current injection probe that is used to inject a RF noise in standard IEC 62132-part 3 documented by International Electrotechnical Commission. Conventional high cost BCI probe has mostly been used in testing automotive ICs that use high supply voltage. We propose a compact microstrip coupler which is suitable for immunity testing of low power ICs. We tested its validity to replace the BCI injection probe from 100 MHz to 1,000 MHz. We compared the power[dBm] that is needed to generate the same level of noise between current injection probe and microstrip coupler by sweeping the frequency. Results show that microstrip coupler can inject the same level of noise into ICs for immunity test with less power.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.25 no.11
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• pp.1156-1163
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• 2014

In this work by measuring transfer impedance of communication cables using EN50289 its Shielding effect is analyzed. transfer impedance measurement triaxial method using EN50289 is defined in CENELEC, it is unlike triaxial method prescribed in IEC Standard 96-1, can be measured regardless of diameter of coaxial cable and outer conductor. in this paper, transfer impedance measurement device of coaxial cable is designed and made according to EN50289 standard, The analysis determines the reliable working frequency range of coaxial cable and examined the impact of different shielding methods on coaxial cable. The transfer impedance measurements show considerable variations in results with various shielding methods. also the measurement procedure is verified through comparison of calculated and measured transfer impedance of RG-58 cable.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.20 no.10
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• pp.107-113
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• 2006

The number of confine-disease for elevator increases every year and then sudden stop, error of level indication stand; those can bring to uneasiness of elevator passenger and malfunction accidents related life accident are increasing. So we researched power quality counterplan equipment(SPD, Filter, Reactor) at site elevator controller room and malfunctions of elevator movement. We could confirm installation of power quality counterplan equipment recently and unchanging the number of malfunction. This data will be used the analysis for mutual relation between Power Quality(Sag, Interruption, ESD, ect.) and malfunction of elevator movement by testing the elevator equipment with EN12016(2004) and IEC standard level.

• Journal of KIISE
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• v.42 no.4
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• pp.459-467
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• 2015

The analysis platform of remote-sensing big data is a system that downloads data from satellites, transforms it to a data type of L3, and then analyzes it and produces its analysis results. The objective of this paper is to develop ISO/IEC 9126-1 software quality model-based assessment criteria, in order to evaluate the quality of remote-sensing big data analysis platform. Its detailed research contents are as follows. First, the ISO/IEC 9216 standards and previous software evaluation models will be reviewed. Second, this paper will define evaluation areas, evaluation elements, and evaluation items for measuring the quality of big data analysis platform. Third, the validity of the assessment criteria will be verified by statistical experiments through content validity, reliability validity, and construct validity, by using SPSS 20.0 and Amos 20.0 software. The construct validity will also be conducted by performing the confirmatory factor analysis and path analysis. Lastly, it is significant that our research result demonstrates the first evaluation criteria in measuring the quality of big data analysis platform. It is also expected that our assessment criteria could be used as the basis information for evaluation criteria in the platforms that will be developed in the future.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.21 no.7
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• pp.75-83
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• 2007

IEC code based decision nile have been widely applied to detect incipient faults in power transformers. However, this method has a drawback to achieve the diagnosis with accuracy without experienced experts. In order to resolve this problem, we propose an artificial diagnosis algorithm to detect faults of power transformers using Self-Organizing Feature Map(SOM). The proposed method has two stages such as model construction and diagnostic procedure. First, faulty model is constructed by feature maps obtained by unsupervised learning for training data. And then, diagnosis is performed by compare feature map with it obtained for test data. Also the proposed method usぉms the possibility and degree of aging as well as the fault occurred in transformer by clustering and distance measure schemes. To demonstrate the validity of proposed method, various experiments are unformed and their results are presented.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.22 no.12
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• pp.36-46
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• 2008

This paper is to study on the Construction of Test circuit and Unification of Experiment Method for high voltage gas-insulated load switch using high power testing system The high power testing system is a equipment to verify electrical and mechanical performance on electrical product. The system consist of short-circuit generator, back-up breaker, making switch, impedance, high voltage transformer, low voltage transformer, measuring and protection system, etc. Using this system, we can test related to high power, for example, short-time current test, active load Current test, magnetizing Current test, capacitive current test, closed loop current test, etc. Standards of high voltage gas-insulated load switch that is in use domestic distribution line are ES 5925-0002, IEC 60265-1, IEC 62271-1 and IEEE C 37.74, etc. In this paper, we standardized on the test procedure, organization of test circuit and analysis of measured data prescribed many difference standards, and applied this test method to 600[MVA] high power testing system. So that we can test the load switch satisfied standards.

• Journal of radiological science and technology
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• v.42 no.4
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• pp.291-299
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• 2019

The International Electrotechnical Commission (IEC) has regulated the definition and requirements of the exposure index (EI). In this study, we calculated the EI of several image receptors in digital radiography system of two different manufacturers according to the method as per IEC, and evaluated the relationship with incident air kerma. To calculate the EI, w e obtained the characteristics curve of each image receptor by increasing the incident air kerma at RQA 3, 5, 7 and 9, respectively. As a result, there was no significant difference in the EI values between different image receptors of the same manufacturer, but EI values of different manufacturer was different despite the same air kerma was incident. Therefore, understanding the characteristics of the digital radiography systems is important in order to use EI as a tool for measuring and managing the radiation dose.

• Journal of the Korean Society of Radiology
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• v.16 no.3
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• pp.303-308
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• 2022

Mammography using X-rays is currently the most used for early diagnosis of breast cancer. As the frequency of use of X-ray devices increases, interest in radiation hazards caused by mammography is increasing. Therefore, in this study, in order to measure the exposure dose of the mammary gland in X-ray mammography that requires high contrast and high resolution, the international Atomic Energy Agency (IAEA) stipulates the international standards presented by IEC 62220-1-2: 2015. Based on the beam quality criteria of the recommendation, we tried to present a guideline for evaluating the average mammary gland dose. As a result, the average streamline dose value of the 4.5 cm PMMA phantom was 2.3 mGy at the maximum within the 30 kV range, and was evaluated to be 1.19 mGy based on 28 kV.